I. Field of the Invention
The present invention relates to a small movable hot deseamer equipped with a nozzle arrangement and an ignition device which is suitable for selective hot deseaming or flame scarfing of defective portions or whole surfaces of steel, and the invention also concerns a method for the use of this machine.
II. Prior Art
In steel mills and rolling mills, hot deseaming devices and/or hot deseamers are used for the flame cutting of workpieces from steel which are mostly semifinished products, such as billets and slab blooms. Hand-operated devices for hot deseaming, which are also called hand deseamers, resemble large cutting torches and possess an igniter wire arrangement by which a short piece of iron wire having a diameter of about 5 mm is inserted into the constant flame of the heating nozzle before the flame producing oxygen is switched on and by which the flame iron wire is maintained at a discharge flow red hot condition. The glowing iron causes the discharge flow, rich in flame producing oxygen, to ignite on the surface of the workpiece. One can use a hand deseamer for carrying out all hot deseaming tasks starting with elimination of individual defective portions of the deseaming of the whole surface and the operator can move his device to various places to be deseamed, i.e., to the respective portion of the workpieces, depending upon the length of his feeding hose lines.
In general, the small quantity of fumes which are produced does not make it necessary to provide for exhaustion of the fumes, and a consumed igniter wire having a length of about 1 meter can be easily replaced with a new one. However, the weight of the device and the feeding hose lines limits the size of the deseaming nozzle, thus limiting the deseaming effect to a strip having the width of about 60 to 90 mm.
Also, hand deseaming becomes heavy physical work which in addition, requires heavy asbestos protective clothing for reasons of safety because the ambient temperature can increase to an undesirable degree by the hot or incandescent workpieces. The presently used process of hand deseaming which can generate heat, glowing scoria, and sparks is especially dangerous because gas and oxygen hose lines are in the immediate proximity of the operator.
Hot deseamers for flame cutting whole surfaces by one pass are very expensive and more or less stationary. They necessitate expensive auxiliary equipment including fume exhausting equipment. Therefore, their use for the deseaming of defective portions is not very practical. The known machines used for the hot deseaming of defective portions or for selective hot deseaming still have the drawbacks of the above hot deseamers which despite high capital investments still need an installation for exhausting fumes because of powder-train ignition. The workpieces have to be transported to the deseamers and the defective portions have to be marked since, under certain circumstances, the operator may stay too far away.